2 [January, 



(2) the colour of the head ; (3) the marks on segment 2 ; (4) the 

 chain of marks down the abdomen ; (5) the intestinal canal ; and (6) 

 a pair of dark lines on the back of the 11th and 12th, or the 11th, 

 12th and 13th segments. The ground colours are yellow and green, in 

 two or three different shades ; both passing at one end of their varia- 

 tion into whitish. Occasionally the green is tinged with blue, as in the 

 bluish-green or almost greenish-blue larva of ulmivora, and to a less 

 extent in p^ri and one or two more. As a rule each species preserves 

 much the same colour all through, but here and there some fading of 

 tint is noticeable as maturity is reached, and doubtless this largely 

 accounts for those occasional errors and discrepancies which meet us 

 in our note books, even if they do not find their way into print. It 

 was on my authority that Mr. Stainton (Ent. Mo. Mag., xxiv, 62) de- 

 scribed the larva of woolhopiella as " very pale green," whereas it is 

 yellow — indeed, a deep yellow for the greater part of its life, but 

 becoming paler towards the last, it borrows something of a greenish 

 tinge from its surroundings, though its true colour is still yellow, as 

 can be ascertained by removing it from the mine. The larva of con- 

 tinuella is a well known example of borrowed colouring, for so deep 

 and pure a green does it look in the mine, that it is hard to believe 

 that it is in reality a rich yellow. 



The Head. — The range of colour extends from pale brown or 

 amber up to grey or black, the mouth parts being usually, if not 

 always, red. A few species are apt to vary to some extent, but by far 

 the greater number are very constant to one tint or shade, so that the 

 value of it as a character is by no means slight. It was but the other 

 day that it did me a very good bit of service. Some doubt has been 

 thrown upon the existence of gratiosella as a good species, mainly from 

 the circumstance that it has been given the larva of an allied species, 

 whilst its own larva seems to have done duty for a presumed summer 

 brood of oxyacantliella. It was noticing the very pale head of this 

 summer-feeding larva that first made me question its identity with the 

 dark headed larva which occurs late in the autumn, and which I knew, 

 beyond dispute, to be the larva of oxyacantliella. Suspicion once 

 aroused, other differencies that had been overlooked or misunderstood 

 before became apparent, until the conviction could no longer be 

 resisted that two very similar larvae and equally similar mines had 

 been mixed up together as one. Subsequently, the breeding of the 

 perfect insect completely settled the point, and proved that the green 

 larva with the colourless head, feeding in the hawthorn leaves in July, 

 belonged to gratiosella. 



